Adult survivors of childhood cancer are at high risk of developing cardiovascular disease. Therapies used to treat many cancers, such as chemotherapy and radiation, likely cause damage to the surface of the artery wall called the endothelial layer, leading to the induction of atherosclerosis and eventual cardiovascular disease. HMG coenzyme A reductase inhibitors, or statins, improve endothelial function independent of cholesterol-lowering. In addition, statins have been shown to reduce arterial stiffness and slow arterial thickening. Despite strong evidence supporting the vascular benefits of statins in many different patient populations, these medications have never been studied in cancer survivors. Therefore, the overall objective of this study is to evaluate the effects of statin therapy on vascular health in young adult survivors of childhood cancer.